Eric Roy, PhD & Analies Dyjak, M.A.   

1. If a water filter can remove red dye, it’s also removing dangerous contaminants. In scientific terms, they’re suggesting that red dye is a “proxy” or “surrogate” for dangerous contaminants.

2. Water filters that do not remove the red color are not as effective as water filters that do remove red food coloring.

Is Red Food Coloring a Representative Proxy or Surrogate for Contaminants in Drinking Water?

Absolutely not. Identifying a representative proxy/surrogate requires that a credible testing body (e.g NSF/ANSI) has actually done experiments to validate it. An example of a representative surrogate test is NSF/ANSI Standard 53 for VOCs, where the certifying bodies have shown (through testing) that chloroform is an effective surrogate for roughly 50 VOCs. No such testing has been done (or to our knowledge attempted) for red food coloring. It goes without saying, if the visual removal of red food coloring was a representative surrogate for water filter performance, credible water filter companies would not be spending millions of dollars on research, development, testing, and evaluation.

Are Water Filters That Do Not Remove Red Food Coloring Less Effective At Removing Dangerous Chemicals?

Absolutely not. For example, one of the brands that prominently markets using the red dye test was part of a water filter evaluation study conducted by Duke and NC State University, and failed miserably. Conversely, various products that do not remove red food coloring (Hydroviv’s included) were effective in filtering “hard-to-filter” PFAS from the challenge solutions. So while the brand effectively removes food-safe red dye, it isn’t able to remove PFAS. In fact, higher levels of PFAS were detected in the filtered water because the filtration media was likely oversaturated. In short, red dye is extremely easy to remove and is not an actual indication of filter performance or contaminant removal.

Is There a Quick and Easy Way To See if My Filter is Working?

While we wish there was an at-home test that could determine if your filter is doing its job, that unfortunately isn’t the case. Every home in America would test their water on a regular basis if at-home test kits provided actual information about water quality. If you want to test for contaminants, you’ll need to send a water sample to an accredited laboratory and test for a range of contaminants. This can cost thousands of dollars and doesn’t provide immediate results. The best way to ensure that you’re using an effective product is to buy products from companies that use third party testing & certifications.

Summary: The Red Dye Test is a Marketing Gimmick

The red dye test tells us almost nothing about filtration performance and shouldn’t be used as a proxy/surrogate for harmful contaminants.

Analies Dyjak, M.A. | Head of Policy   

The State of Massachusetts recently implemented new testing requirements and water quality standards for 6 different PFAS variations. PFAS (Per and Polyfluoroalkyl Substances) are a federally unregulated contaminant known to cause adverse health effects, including cancer. These new requirements have forced municipalities to take a closer look at the safety of their drinking water. This article will address what PFAS compounds are, the "safe" levels in Massachusetts drinking water, and water filtration brands that actually remove them. 

PFAS in Massachusetts

Massachusetts became one of the first states to adopt drinking water standards for PFAS chemicals in January, 2021. Prior to January of this year, municipal water suppliers throughout Massachusetts were not required to test for PFAS compounds until January 2021, when the state implemented these requirements. Up until that point, people in Wayland did not know they were being exposed to this potentially cancer-causing substance. 

In October, 2020, the Massachusetts Department of Environmental Protection set an enforceable standard of 20 parts per trillion for the sum of six PFAS compounds in drinking water. The six compounds, called PFAS6, are: PFOS, PFOA, PFHxS, PFNA, PFHpA, and PFDA. This regulation means that if a water sample exceeds 20 parts per trillion for all six compounds, that the municipal provider is in violation of the state law. The table below shows elevated levels of PFAS in Wayland source water. A more detailed and thorough analysis of these results can be found on the Wayland, MA, website dedicated to PFAS testing.  

What Are Per and Polyfluoroalkyl Substances?

Per and Polyfluoroalkyl Substances (PFAS) are a category of harmful compounds that can be found in drinking water sources across the country. PFAS can take hundreds of years to degrade in the environment which is why you may see them referred to as ‘forever chemicals.’ PFAS are not currently regulated at the federal level, but some states have created regulations or monitoring criteria, including Massachusetts. They are known to increase the risk of cancer, increase cholesterol, increase the risk of miscarriage by 80-120%, and several other negative health outcomes. According to the National Institute of Health, over 4,700 different PFAS variations have been used in some type of manufacturing since the 1950’s.

Is 20 ppt Safe?

There’s a bit of uncertainty around the “safe level” of exposure to PFAS compounds. There are only a handful of studies that assess associated health impacts, and most agree that more research is necessary to make a determination. In 2016, EPA set a non-enforceable Health Advisory Level of 70 parts per trillion for combined PFOA and PFOS. More recent data suggests that this level is far to high to provide meaningful protection against a range of negative health impacts. A recent study also found that a “safe level” or PFAS could be as low as 0.1 parts per trillion. Although the Massachusetts PFAS standard is on the lower end of state limits, our team would rather see even less PFAS allowed in municipal tap water. 

Not All Water Filters Remove PFAS

If you live in Wayland and you’re looking for a solution, it’s important to understand that not all water filters are able to remove PFAS chemicals. Duke University completed a study in 2020 that tested various filtration brands and their ability to remove PFAS from drinking water. The results found that popular brands including Brita and Pur did not do a good job of removing PFAS compounds. Refrigerator filters tested by the Duke research team, including; Samsung, Whirlpool, and GE, also failed to remove PFAS. The full results of this study can be found here. Hydroviv filters are both NSF certified and third-party tested to remove PFAS chemicals. To request our full testing and removal data, please email hello@hydroviv.com.